Ingrid Betancourt delivered a message in a videotape that was broadcast by Colombian television Sunday, the BBC reported.
It was the first indication in more than a year that Betancourt was still alive. She was last seen in a video released in July 2002.
Her captors, members of Revolutionary Armed Forces of Colombia, have demanded rebel prisoners be released in exchange for Betancourt.
In the videotape, Betancourt called on President Alvaro Uribe to order a rescue mission.
"A rescue, yes, definitely, but not just any rescue," she said. "It's important that it be the president who directly makes this decision. I believe it is not a military decision, but a political one."
It was unknown when the tape was made, the BBC said.